JPH11189613A - Production of hydroxyl-containing polymer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the formyl groups of a formyl-containing polymer into hydroxymethyl groups in high conversion without any crosslinking reaction by catalytically hydrogenating the polymer in the presence of an alcohol and a hydrogenation catalyst. SOLUTION: The formyl-containing polymer can be produced by, for example, a known process comprising hydroformylating a polymer having aliphatic carbon - carbon double bonds in the molecule and obtained by polymerizing a conjugated diene such as 1,3-butadiene, isoprene, or 1,3-pentadiene. The alcohol is exemplified by a primary or secondary monohydric alcohol such as methanol, ethanol, or 2-propanol or a dihydric alcohol such as ethylene glycol or 1,4-butanediol. Among them, a primary or secondary monohydric alcohol is desirable. The hydrogenation catalyst is exemplified by Raney nickel, Raney cobalt, ruthenium carbon, or palladium carbon.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a hydroxyl group-containing polymer by catalytic hydrogenation of a formyl group-containing polymer (hereinafter abbreviated as a formyl group-containing polymer).

[0002]

2. Description of the Related Art Hydroxyl-containing polymers are useful as raw materials for polyurethane and the like, and can be produced by various methods. As one of such methods, a method of hydrogenating a formyl group-containing polymer is known, for example,
JP-A-6-49168 describes a method for producing a hydroxyl group-containing polymer by subjecting a formyl group-containing polymer obtained by hydroformylating EPDM to catalytic hydrogenation in toluene.

[0003]

The present inventors have paid attention to the technology disclosed in the above-mentioned publication and tried to hydrogenate a formyl group-containing polymer under the reaction conditions described in the publication. As a result, in an attempt to increase the conversion of the formyl group, -C-
In the case of a formyl group-containing polymer, the higher the formyl group content, the stronger this tendency is, and the higher the formyl group content, the better the yield of the hydroxyl group-containing polymer obtained by hydrogenating almost 100% of the formyl group. I couldn't get it.
Thus, the present invention provides a method for producing a hydroxyl group-containing polymer by catalytic hydrogenation of a formyl group-containing polymer, without involving the above-mentioned crosslinking reaction, and converting a formyl group into a hydroxymethyl group at a high conversion rate. It is an object to provide a method that can be reduced.

[0004]

According to the present invention, an object of the present invention is to provide a method for producing a hydroxyl group-containing polymer, comprising catalytically hydrogenating a formyl group-containing polymer in the presence of an alcohol and a hydrogenation catalyst. It is solved by providing.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION The formyl group-containing polymer used as a raw material in the present invention includes those having an aliphatic carbon-carbon double bond in the molecule. The formyl group-containing polymer is obtained by polymerizing a conjugated diene such as 1,3-butadiene, isoprene, 1,3-pentadiene, 2,3-dimethylbutadiene and phenylbutadiene. It can be produced by a known method such as a method of subjecting a polymer having a carbon double bond to a hydroformylation reaction to introduce a formyl group. In the above, as a polymer before introducing a formyl group, not only a conjugated diene homopolymer, but also a copolymer of two or more conjugated dienes may be used,
A copolymer of a conjugated diene and a vinyl monomer may be used. Here, as the vinyl monomer, for example, styrene, α-methylstyrene, vinyltoluene, vinylnaphthalene, cumarone, indene, vinylpyridine, vinylfuran, acrylonitrile, methyl acrylate, ethyl acrylate, methyl methacrylate, hydroxyethyl acrylate , Hydroxyethyl methacrylate,
Examples include acrylic acid, methacrylic acid, ethylene, propylene, isobutylene, vinyl acetate, vinyl chloride, and maleic anhydride. In the case of a copolymer of two or more conjugated dienes or a copolymer of a conjugated diene and a vinyl monomer, there is no particular limitation on the ratio of the monomer as a constituent component. The amount of the monomer is preferably 95% by weight or less, more preferably 80% by weight or less, based on the total amount of the monomer. The structure of the copolymer is not particularly limited, and may be any of block, random, and tapered.

[0006] The number average molecular weight (M
n) is not particularly limited, but is usually 500
１，1,000,000, and 1,000-5
It is preferably in the range of 00,000. Here, the number average molecular weight of the formyl group-containing polymer is,
It is a number average molecular weight in terms of polystyrene measured by gel permeation chromatography (GPC). Further, the formyl group-containing polymer may have a substituent such as a carboxyl group as long as it does not adversely affect the catalytic hydrogenation reaction.

There is no particular limitation on the number of formyl groups (N _CHO ) in the formyl group-containing polymer. The formyl group-containing polymer may contain an aliphatic carbon-carbon double bond in the molecule, and the number thereof (N _{C = C} ) is not particularly limited. (N _CHO ) (ie, N _CHO + N _{C = C} ), usually 2
000 or less, preferably from 10 to 10,000.
0. The ratio of the number of formyl groups to the total number of formyl groups (N _CHO ) and the number of aliphatic carbon-carbon double bonds (N _{C = C} ) CC _CHO = [N _CHO / (N _CHO + N
_{C = C} )] × 100, unit%} is usually 0.01 or more, preferably 1 to 99, more preferably 5 to 95.

In the present invention, the formyl group-containing polymer is catalytically hydrogenated in the presence of an alcohol and a hydrogenation catalyst to reduce the formyl group to a hydroxymethyl group. At this time, the aliphatic carbon-carbon double bond in the formyl group-containing polymer may be hydrogenated.

The alcohol used in the present invention includes, for example, methanol, ethanol, 2-propanol,
Primary or secondary monohydric alcohols such as butanol; ethylene glycol, 1,4-butanediol, 2,3-
Examples thereof include dihydric alcohols such as butanediol, diethylene glycol, and polyethylene glycol.
Primary or secondary monohydric alcohols are preferred. The amount of the alcohol used is not particularly limited, but may be 0.5 to 1 with respect to 1 mol of formyl group in the formyl group-containing polymer.
The amount is preferably 0 mol, more preferably 1 to 5 mol per 1 mol of formyl group in the formyl group-containing polymer.

As the hydrogenation catalyst used in the present invention, those conventionally used for catalytically hydrogenating a formyl group to reduce it to a hydroxymethyl group can be used. Nickel, Raney cobalt, ruthenium carbon, palladium carbon and the like can be mentioned. These catalysts may be used alone or 2
More than one type may be used in combination. The amount of hydrogenation catalyst used is
The content of the formyl group in the formyl group-containing polymer, the content of the aliphatic carbon-carbon double bond and the like vary, but is usually 100 ppm to 25 ppm based on the formyl group-containing polymer.
%, Preferably from 1 to 15% by weight based on the formyl group-containing polymer.

[0011] The catalytic hydrogenation reaction according to the present invention may be carried out in the presence of a solvent in addition to the above alcohol. Examples of usable solvents include ethers such as diethyl ether, di-n-butyl ether, diisopropyl ether, diisoamyl ether, diphenyl ether, anisole, ethyl phenyl ether, amyl phenyl ether, tetrahydrofuran, tetrahydropyran, 1,4-dioxane and trioxane. Hexane, heptane,
Examples thereof include hydrocarbon solvents such as octane, cyclohexane, methylcyclohexane, benzene, toluene, and xylene. The amount of the solvent to be used is not particularly limited, but is usually within 100 times the weight of the alcohol, preferably within the range of 0.1 to 10 times the weight of the alcohol.

The catalytic hydrogenation reaction according to the invention is usually carried out at a temperature in the range from room temperature to 250 ° C.
It is preferred to carry out at a temperature in the range of -200 ° C.

The catalytic hydrogenation reaction according to the present invention may be carried out under normal pressure or under pressure.
It is preferably carried out under a hydrogen pressure in the range of 300 kg / cm ² G (gauge pressure), from normal pressure to 100 kg / cm ^2.
More preferably, it is carried out under a hydrogen pressure in the range of G.
The catalytic hydrogenation reaction according to the present invention can be performed in a stirred reactor with the catalyst suspended in the liquid phase, or can be performed in a fixed-bed reactor filled with a supported catalyst. it can. In addition, any of a continuous method and a batch method may be used.

The hydroxyl group-containing polymer obtained by the catalytic hydrogenation reaction according to the present invention can be obtained by treating the reaction mixture after the completion of the hydrogenation reaction according to a conventional method. That is, if necessary, the catalyst is removed from the reaction mixture by a means such as filtration, and then, by removing the alcohol or the solvent by a method such as heat drying and steam stripping, a hydroxyl group-containing polymer can be obtained. .

According to the catalytic hydrogenation reaction of the present invention, at least 85%, usually 90% or more, of the formyl groups in the raw material formyl group-containing polymer can be hydrogenated without causing a crosslinking reaction. Further, at least 90%, usually 98% of the aliphatic carbon-carbon double bond in the polymer.
The above can be hydrogenated.

[0016]

EXAMPLES The present invention will be described in detail below with reference to examples, but the present invention is not limited to these examples.

Reference Example 1 In a 300 ml stainless steel autoclave equipped with a thermometer, an electromagnetic stirrer and a gas inlet, 6.2 mg of rhodium dicarbonylacetylacetonate (0.0 mg) was added.
24 mmol) and 155.2 mg (0.24 mmol) of tris (2,4-di-t-butylphenyl) phosphite were dissolved in 112 ml of 1,4-dioxane in advance and polybutadiene (non-aqueous solution). Additives, number average molecular weight: 2000, 1,2-bond content: 90 mol%) 5
0 g was charged in a hydrogen / carbon monoxide mixed gas (molar ratio = 1/1) atmosphere. Next, a hydrogen / carbon monoxide mixed gas (molar ratio = 1/1) was introduced into the autoclave, the internal pressure was adjusted to 90 absolute pressure, and the internal temperature was adjusted to 90 atm under stirring.
The temperature was raised to ° C. The internal temperature is maintained at 90 ° C.
The reaction was carried out for 2 hours while continuously supplying a hydrogen / carbon monoxide mixed gas (molar ratio = 1/1) so as to be maintained at an absolute pressure, and about 30 carbon-carbon double bonds of polybutadiene as a raw material were obtained. % (Calculated from the absorption amount of the hydrogen / carbon monoxide mixed gas) to give a 1,4-dioxane solution of a hydroformylated polymer (hereinafter abbreviated as polymer A).

Reference Example 2 Except that the reaction time was changed from 2 hours to about 5 hours,
In the same manner as in Reference Example 1, 50 g of polybutadiene (unhydrogenated product, number average molecular weight: 2000, 1,2-bond content: 90 mol%) was hydroformylated (hydroformylation ratio of carbon-carbon double bond: about 50%) and a 1,4-dioxane solution of a formyl group-containing polymer (hereinafter abbreviated as polymer B).

Example 1 In a 300 ml-volume autoclave, the total amount of the 1,4-dioxane solution of the polymer A obtained in Reference Example 1, 10 g of Raney nickel (water content: 50%) and methanol 1
8 g (2 mol per 1 mol of formyl group in polymer A) was charged, and then hydrogen was supplied into the autoclave to increase the pressure in the autoclave to 70 kg / cm ² G.
(Gauge pressure). Thereafter, the temperature in the autoclave is increased to 170 ° C., and hydrogen is supplied into the autoclave to maintain the pressure in the autoclave at 90 kg / cm ² G (gauge pressure). Hydrogenation reaction was carried out until. After completion of the reaction, the catalyst (Raney nickel) was removed from the reaction mixture by filtration, and then the solvent and methanol were distilled off to obtain 45 g of a hydrogenated product. GPC for the hydrogenated product obtained
As a result of the measurement, no compound having a high molecular weight was found, and it was found that no cross-linking occurred. Also,
From the infrared absorption spectrum of this hydrogenated product, no carbon-carbon double bond remaining in the molecule was observed, and the hydrogenation rate of the carbon-carbon double bond in polymer A was 100%. I understand. Further, from the hydroxyl value (see Table 1 below) of the hydrogenated product, 90% of the formyl group in the polymer A was determined.
It was found that the above was hydrogenated.

Example 2 In Example 1, the entire amount of the 1,4-dioxane solution of the polymer B obtained in Reference Example 2 was used in place of the 1,4-dioxane solution of the polymer A, and methanol was used. Use 6
45 g of a hydrogenated product was obtained in the same manner as in Example 1, except that the amount was changed to 0 g (the amount became 4 mol per 1 mol of formyl group in the polymer B). GPC measurement was performed on the obtained hydrogenated product, and it was found that a crosslinked product was not generated as in Example 1. Also, from the infrared absorption spectrum of this hydrogenated product, the carbon-
No carbon double bond was observed, and it was found that the hydrogenation ratio of the carbon-carbon double bond in the polymer B was 100%. Further, the hydroxyl value of this hydrogenated product (see Table 1 below)
From this, it was found that 90% or more of the formyl groups in the polymer B were hydrogenated.

Example 3 In Example 1, the total amount of the 1,4-dioxane solution of the polymer A obtained by repeating the method of Reference Example 1 again was used, and 2-propanol 3 was used instead of 18 g of methanol.
45 g of a hydrogenated product was obtained in the same manner as in Example 1, except that 4 g (2 mol per 1 mol of formyl group in the polymer A) was used. GPC measurement was performed on the obtained hydrogenated product, and it was found that a crosslinked product was not generated as in Example 1. From the infrared absorption spectrum of this hydrogenated product, no carbon-carbon double bond remaining in the molecule was observed, and the hydrogenation rate of the carbon-carbon double bond in the polymer A was 100%. I understood that. Further, the hydroxyl value of this hydrogenated product (see Table 1 below)
It was found that 90% or more of the formyl groups in the polymer A were hydrogenated.

Comparative Example 1 45 g of a hydrogenated product was obtained in the same manner as in Example 1 except that methanol was not used and the amount of Raney nickel used was 15 g. When the obtained hydrogenated product was subjected to GPC measurement, a compound having a molecular weight exceeding 10,000 was detected, and it was found that a crosslinked product had been formed.

Comparative Example 2 In Example 2, 45 g of a hydrogenated product was obtained in the same manner as in Example 2, except that methanol was not used and the amount of Raney nickel used was 15 g. It was found that the obtained hydrogenated product contained a component that did not dissolve in tetrahydrofuran (THF), which was a solvent at the time of GPC measurement, and a gel was formed by crosslinking. Also, TH
GPC measurement was performed on the component dissolved in F, and a compound having a molecular weight exceeding 30,000 was detected.

[0024]

[Table 1]

[0025]

According to the present invention, a formyl group-containing polymer is hydrogenated at a high hydrogenation rate without a crosslinking reaction, and a hydroxyl group formed by reducing a formyl group to a hydroxymethyl group at a high conversion rate. The contained polymer can be obtained with high yield.

Claims (2)

[Claims] 1. A process for producing a hydroxyl group-containing polymer, comprising catalytically hydrogenating a polymer having a formyl group in the presence of an alcohol and a hydrogenation catalyst. 2. The method according to claim 1, wherein the hydrogenation catalyst is at least one catalyst selected from the group consisting of Raney-nickel, Raney cobalt, ruthenium carbon and palladium carbon.